THE FREE MESH WORKBENCH
STL checker
& 3D viewer.
Inspect the starting point. Rotate your mesh, confirm its size, and understand what to check before moving into CAD.
Binary or ASCII · up to 100 MB / 500,000 triangles
Your file stays in your browser. This tool never uploads it.
What the tool checks
Triangle count, bounding dimensions, and surface area. For smaller meshes, it also counts boundary and non-manifold edges. The preview may sample faces to stay responsive; statistics use the full parsed model.
STL does not reliably identify physical units. Choose the intended units and compare a known measurement. An edge check is a useful diagnostic; it does not test every possible geometry defect.
What to do next
If you need a one-off cut, try a CAD conversion. If you need easier control over repeated design changes, consider rebuilding the part around those dimensions.
Read the STL-to-STEP workflow →Request a mechanical part review →